cosmwasm_std/
iterator.rs

1use crate::StdError;
2use schemars::JsonSchema;
3use serde::{Deserialize, Serialize};
4
5/// A record of a key-value storage that is created through an iterator API.
6/// The first element (key) is always raw binary data. The second element
7/// (value) is binary by default but can be changed to a custom type. This
8/// allows contracts to reuse the type when deserializing database records.
9pub type Record<V = Vec<u8>> = (Vec<u8>, V);
10
11#[derive(
12    Serialize, Deserialize, Clone, Copy, Debug, PartialEq, Eq, JsonSchema, cw_schema::Schemaifier,
13)]
14#[serde(rename_all = "snake_case")]
15// We assign these to integers to provide a stable API for passing over FFI (to wasm and Go)
16pub enum Order {
17    Ascending = 1,
18    Descending = 2,
19}
20
21impl TryFrom<i32> for Order {
22    type Error = StdError;
23
24    fn try_from(value: i32) -> Result<Self, Self::Error> {
25        match value {
26            1 => Ok(Order::Ascending),
27            2 => Ok(Order::Descending),
28            _ => Err(StdError::msg("Order must be 1 or 2")),
29        }
30    }
31}
32
33impl From<Order> for i32 {
34    fn from(original: Order) -> i32 {
35        original as _
36    }
37}
38
39#[cfg(test)]
40mod tests {
41    use crate::{from_json, to_json_vec};
42
43    use super::*;
44
45    #[test]
46    fn order_serde() {
47        let ascending_bytes = br#""ascending""#;
48        let descending_bytes = br#""descending""#;
49
50        assert_eq!(to_json_vec(&Order::Ascending).unwrap(), ascending_bytes);
51        assert_eq!(to_json_vec(&Order::Descending).unwrap(), descending_bytes);
52
53        assert_eq!(
54            from_json::<Order>(ascending_bytes).unwrap(),
55            Order::Ascending
56        );
57
58        assert_eq!(
59            from_json::<Order>(descending_bytes).unwrap(),
60            Order::Descending
61        );
62    }
63}